PoseRay is a format converter to change various 3d scene formats (e.g. Poser, D|S) into scenes and scripts for other rendering applications (e.g. POV-Ray). POV-Ray is a scripted renderer. You need both tools to get POV-Ray to render a poser scene. The preview mode in PoseRay is only really to check that the scene and materials were imported/set correctly and that the camera and light positions are correct. It is POV-Ray that creates a high quality render.